Remove feature flags for release v1.11.0

[koesie10]

This removes the "feature flags" for the CodeQL method modeling and multiple models per method. Both already had their actual feature flags removed but were still behind canary. This removes that check and removes old code that is now unused.

Checklist

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.

[robertbrignull]

The code changes and deleted code looks good to me.

I haven't tried running it but I trust you have tested it, and also we'll be doing some testing before the release.